Remote monitoring of the operation and location of vehicles has long been considered desirable by those charged with managing vehicle fleets. For example, remote monitoring systems have been used in trucks engaged in interstate travel to monitor engine functions by remotely accessing data recorded from sensors placed within the engine. Truck fleet managers can use this data to evaluate engine performance and necessary maintenance schedules. One concern of truck fleet managers is excessive idling of heavy duty truck engines which results in increased fuel usage and maintenance costs. A way to control these costs is to automatically turn the engine off after a predetermined amount of idle time. For example, existing engine control systems such as those developed by the assignee, Cummins Engine Company, detect unattended idling and stop the engine after a predetermined time. Such systems make use of an electronic data link and control system such as that disclosed in SAE Technical Paper Series 902215, "Data Link Overview for Heavy Duty Vehicle Applications," by Mark R. Stepper, Cummins Electronics Co., Inc.
Many truck operators, however, need to idle the engine for long periods of time to heat or cool the truck cabin. To facilitate idling for this purpose, some idle shutoff systems are provided with an override feature. As an example, a warning light may be illuminated thirty seconds before the engine is to be shut down after a long period of idling. Then, if the driver presses the accelerator or brake pedal while the warning light is on, the idle shutdown is bypassed. None of these alternatives are entirely satisfactory. If the control system is not provided with an override feature to prevent automatic shutdown, it may be impossible to maintain a desired temperature in a sleeper cab, making it necessary for the driver to rent a motel room at considerable cost. However, if the driver is able to override an automatic shutdown, the system will not be highly effective for reducing operating costs since the driver can override the automatic shutdown at will, even in situations where an override is not appropriate.
U.S. Pat. No. 4,258,421 discloses an on-board system comprising a plurality of sensors, a data processing and recording device, a portable data link and a central computing apparatus, which analyzes the data and provides summary reports. The sensors detect the vehicle's operating parameters and generate data signals. The data processing and recording device processes the data signals. The portable data link reads stored data signals into a non-volatile memory from which they can be downloaded to the central computing apparatus, which analyzes the data and provides summary reports. The system disclosed in U.S. Patent No. 4,258,421 does not provide real-time monitoring, nor does it transmit data to a vehicle for modifying existing engine control parameters.
Systems of the type shown in U.S. Pat. No. 4,804,937 improve upon the aforementioned design by allowing a base station to transmit driver instructions and control sensor calibration in a plurality of vehicles from a central location. A plurality of communication modules attached to a standardized data bus in the vehicle transmit operating status information to a control module. The communications control module records the transmitted information and subsequently transmits the information to a base station via a radio frequency (RF) transmitter. The system also includes a driver interface module for transmitting information to and from a vehicle operator and a recorder for receiving and recording information supplied by the communications modules. However, like the system in U.S. Pat. No. 4,258,421, this system fails to provide a system for remotely varying vehicle engine operating algorithms, that is, the system is not able to modify the sequence of operating commands implemented by a computer operated engine controller.
Systems have also been developed for starting engines by remote control. U.S. Pat. No. Re. 30,686 discloses a remote control starting system for a vehicle engine which can also stop the engine under specified circumstances. Specifically, the starting system is activated by a coded control signal from a transmitter carried by the user. Once activated, the starter system stops the engine after a predetermined time period has lapsed. Nevertheless, systems of the type disclosed in U.S. Pat. No. Re. 30,686 do not provide the capability to remotely override and/or modify an existing engine control algorithm and do not control multiple vehicles from a central dispatch station.
Accordingly, there is a need for an improved system that overcomes these problems and deficiencies in present systems.